Question: Who uses Pellagra?
Paraphrase: By whom is Pellagra used?
SPARQL (Wikidata): SELECT ?answer WHERE { wd:Q221441 wdt:P2176 ?X . ?X wdt:P2868 ?answer}
Answer: vitamin B, vitamin B, hypolipidemic, vasodilator agent, Vitamin B3 complex, vitamin B, Enzyme activator